NASA Technical Reports Server (NTRS) 20150002536: Thermodynamics in the Suppressed Phase of the Madden-Julian Oscillation Using a Multiplatform Strategy

AGU Fall Meeting 2014
15-19 Deeember 2014
San Franeiseo, CA
Moseone Center

Session: Advances in Weather and Climate Science Enabled by Atmospheric Profilers
Session Deseription:

Atmospheric temperature, humidity and cloud profilers operating on satellites provide some
of the most important data for numeric weather prediction, but they also play a crucial role In
the study of atmospheric phenomena that control and define weather and climate and
provide a unique view of their vertical structure. For this session we Invite contributions that
highlight new results in a broad variety of studies of atmospheric processes and
intraseasonal to interannual climate variability using observations from infrared sounders,
such as the Atmospheric Infrared Sounder (AIRS), microwave sounders, such as the
Advanced Microwave Sounding Unit (AMSU), and radar, such as CloudSat. Examples of
relevant topics are moist thermodynamic processes, the Madden-Julian Oscillation (MJO)
and the El Nino Southern Oscillation (ENSO). Many such studies will make use of data from
complementary sensor systems as well. We also encourage contributions that show how
reanalysis data contrast with or complement the satellite data.

Authors

J. Brent Roberts', Franklin R. Robertson', Carol Anne Clayson^, Patriek Taylor^

' NASA/MSFC, Earth Seienee Office
^ Woods Hole Oceanographic Institution
^ NASA Langley Research Center

Title

Thermodynamics in the suppressed phase of the Madden-Julian Oscillation using a
multiplatform strategy

Abstract

The Madden-Julian Oscillation (MJO) represents a prominent mode of
intraseasonal tropical variability. It is manifest by coherent large-scale changes in
atmospheric circulation, convection, and thermodynamic processes. Preconditioning of
the environment prior to the active phase of the MJO has been noted, but the balance of
theorized mechanisms to accomplish this process remains unresolved. Further, there is a
lack of consensus on the means by which primary initiation of an MJO event occurs.
Observational and modeling efforts have recently been undertaken to advance our
understanding of the physical underpinnings governing MJO development. However
these intensive studies are often limited in space and/or time and are potentially subject to
model deficiencies. Satellite observations, especially those providing vertical resolution
of temperature and moisture, provide an opportunity to expand our knowledge of
processes critical to MJO initiation and preconditioning.

This work will provide an analysis of suppressed phase thermodynamics with an
emphasis on the use of a complementary suite of satellite observations including
AIRS/AMSU-A profiles, CERES radiative fluxes, and cloud properties observed by
MODIS. Emphasis of this work will regard the distribution of cloud regimes, their

radiative-convective effects, and their relationship to moist static energy during the
recharge and suppressed stages of MJO initiation and eastward propagation. The analyses
will make use of cloud regimes from MODIS observations to provide a compositing
technique that enables the identification of systematic connections between different
cloud regimes and the larger scale environment. Within these cloud regimes, the
relationship between the associated cloud-radiative effects observed by CERES,
vertically-resolved and vertically-integrated thermodynamics using AIRS/AMSU-A
observations, and atmospheric boundary layer fluxes will be demonstrated.